1. Field of the Invention
The present invention generally relates to amorphous silicon carbide thin films and articles comprising amorphous silicon carbide thin films, as well as to methods of making and using the same.
2. Description of the Art
Silicon carbide (SiC) is an extremely hard, mechanically strong, and chemically inert ceramic material. Silicon carbide exhibits good oxidation resistance and corrosion resistance, high heat transfer coefficient compared to metals, low expansion coefficient compared to metals, high resistance to thermal shock and high strength at elevated temperatures.
Although silicon carbide has come into use as a wafer material for semiconductor device manufacturing, it has not been extensively utilized in a manner that reflects its commercial potential and variant properties.
The present invention is directed to novel applications of silicon carbide in the form of amorphous silicon carbide thin films.
The present invention relates to amorphous silicon carbide thin films in a variety of products and end use applications, in which the physical, chemical, electrical and/or optical properties of amorphous silicon carbide are utilized to advantage.
In one aspect, the present invention relates to an article comprising an amorphous silicon carbide thin film on a structure selected from the group consisting of:
substrates that are transmissive to at least one of light and infrared radiation;
structures adversely affected by exposure to radio frequency and/or microwave radiation thereon;
shielding members for protection of structures adversely affected by exposure to radio frequency and/or microwave radiation thereon;
structures susceptible to chemical attack and/or thermal degradation in their end use environments; and
electronic circuitry structures susceptible to diffusional release and/or diffusional receipt of atomic species in use thereof.
Another aspect of the invention relates to a window assembly, comprising:
a window; and
an optically transparent thin film of amorphous silicon carbide on a surface of said window.
In a further aspect, the invention relates to a window assembly, comprising:
a window;
an optically transparent and electrically conductive thin film of amorphous silicon carbide deposited on a surface of said window; and
a power supply operatively coupled to the thin film, and selectively actuatable so that the power supply when actuated causes an electrical current to flow through the thin film to generate heat, whereby the window may be selectively defogged or de-iced.
Another aspect of the invention relates to an electromagnetic interference shielded assembly, comprising:
a structure disposed in protective relationship to a region to be shielded; and
an electrically conductive thin film of amorphous silicon carbide on at least a portion of said structure.
A further aspect of the invention relates to a sensor assembly, comprising:
a sensor; and
an amorphous silicon carbide thin film on at least part of the sensor.
Yet another aspect of the invention relates to a sensor assembly, comprising:
a sensor including sensing element(s) formed of amorphous silicon carbide, whereby the sensor assembly is operable at temperatures up to 1000xc2x0 C.
In another aspect, the invention relates to a high-temperature sensor assembly, comprising:
a sensing element formed of amorphous silicon carbide; and
electrical circuitry operatively coupled with the sensing element,
said electrical circuitry comprising amorphous silicon carbide doped with at least one dopant selected from the group consisting of n-type and p-type dopants, whereby the sensor assembly is operable at temperatures up to 1000xc2x0 C.
A further aspect of the invention relates to a high-temperature pressure sensor, comprising:
a substrate including a reference cavity region;
a first highly resistive amorphous silicon carbide thin film deposited on the substrate, but not the reference cavity region;
a second highly resistive amorphous silicon carbide thin film deposited over the first highly resistive thin film, and additionally over the reference cavity region, to form a sealed reference cavity;
a low resistivity amorphous silicon carbide thin film deposited over the second highly resistive thin film, over the region of the sealed reference cavity; and
electrodes contacting the low resistivity amorphous silicon carbide thin film, and operatively coupled to a resistance-sensing electrical circuit,
whereby changes in resistivity of the low resistivity amorphous silicon carbide thin film incident to changes in strain in the low resistivity amorphous silicon carbide thin film are sensed by the resistance-sensing circuit.
Another aspect of the invention relates to a VLSI circuit assembly, comprising:
a VLSI electronic circuit including an active circuit structure and a metalization interconnect layer; and
a thin film of amorphous silicon carbide between the active circuit structure and the metalization layer, as a diffusion barrier against diffusion of atoms from the metalization layer into the active circuit structure.
In another aspect, the invention relates to a method of forming an article comprising an amorphous silicon carbide thin film, including deposition of the amorphous silicon carbide thin film by a process selected from the group consisting of chemical vapor deposition, plasma enhanced chemical vapor deposition, RF glow discharge, RF sputtering, ion cluster beam deposition, ion beam sputtering, sol gel coating, reactive sputtering, plasma spray, reactant spraying, microwave discharge, and photo CVD.
Other aspects, features and embodiments of the invention will be more fully apparent from the ensuing disclosure and claims.